Metadata indexing / parse resource maintenance date of next update to check that is valid.

[josegar74]

Analog to #8598 to parse resource maintenance date of next update to check that is valid, otherwise if the search results return the metadata with the issue, the search response is returned.

Search response error:

java.lang.NullPointerException
	at org.fao.geonet.api.es.EsHTTPProxy.lambda$processResponse$0(EsHTTPProxy.java:696)
	at org.fao.geonet.api.es.JsonStreamUtils.filterTree(JsonStreamUtils.java:147)
	at org.fao.geonet.api.es.JsonStreamUtils.lambda$addInfoToDocs$1(JsonStreamUtils.java:109)
	at org.fao.geonet.api.es.JsonStreamUtils.filterArrayElements(JsonStreamUtils.java:50)
	at org.fao.geonet.api.es.JsonStreamUtils.lambda$addInfoToDocs$2(JsonStreamUtils.java:108)
	at org.fao.geonet.api.es.JsonStreamUtils.filterObjectInPath(JsonStreamUtils.java:74)

Index error of a metadata with invalid resource maintenance date of next update with an invalid date value (2025-02-11):

2025-02-10T14:16:02,494 ERROR [geonetwork.index] - Document with error #be1b1514-8d1f-48e1-9624-fee9b784138c: [1:5095] failed to parse field [maintenance.nextUpdateDate] 
of type [date] in document with id 'be1b1514-8d1f-48e1-9624-fee9b784138c'. Preview of field's value: '(2025-02-11)'.

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Resource maintenance indexing was added to 4.4.x in #8293

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